Two-color matrix-type display panel

ABSTRACT

A PLASMA DISPLAY APPARATUS IN WHICH A COLOR DISPLAY IS ACHIEVED BY SANDWICHING DIFFERENT GASES BETWEEN X AND Y MATRIX CONDUCTORS. THE GASES ARE CHOSEN SUCH THAT EACH GAS GIVES OFF A DIFFERENT COLOR WHEN IONIZED.

United States Patent Inventor Donald D. Tech Rhinebeck, N.Y.

Appl. No. 772,786

Filed Nov. 1, 1968 Patented June 28, 1971 Assignee International Business Machines Corporation Arm'onk, NX.

TWOCOLOR MATRIX-TYPE DISPLAY PANEL 11 Claims, 3 Drawing Figs.

U.S.CI. .1 315/169, 313/108 Int. Cl ..H0lj 11/02, H01 j 1 1/04 Field oiSearch 313/234,

108(8); 328/118; 315/130-133, 84.6, 169, 174, 334, 337, 169 TV 340/324, 343, 344, 166 (Orig), 166 (EL) [56] References Cited UNITED STATES PATENTS 1,906,046 4/1933 Chromy 315/337X 3,015,747 H1962 Rosenberg... 313/108 3,445,682 5/1969 Kohn el al. .1 307/236 OTHER REFERENCES Bitzer et aL, Plasma Display Panel A Digitally Addressable Display with Inherent Memory" article in AFlPS Conference Proceedings, Vol. 29, (1966) Fall Joint Computer Conference.

Primary Examiner- John W. Huckert Assistant Examiner-W. Larkins Attorneysl-lanifin and Jancin and Owen L. Lamb ABSTRACT: A plasma display apparatus in which a color display is achieved by sandwiching different gases between X and Y matrix conductors. The gases are chosen such that each gas gives off a difierent color when ionized.

GAS CHAMBER OAS 0F COLOR PHASE 56 smrrsa 1 CONTROL GAS CHAMBER GAS OF COLOR K2 F l G. osc

GAS CHAMBER swncnmc GAS OF com a & M

suacnou CONTROLS X-AXIS 7 CONTROL GAS CHAMBER GAS 0F COLOR x2 2 0 Y2- AXIS CONTROL mm; FIG.3

L\ y: 1"1 ["l I f Y4 Mus Y r I 1 X- AX|3 fi FIG.2 M v 757;" A 24 J 2e VFZ COLOR k B 4 Y AXIS w coLoR x INVENTOR t W DONALD D TECH ATTORNEY TWO-COLOR MATRIX-TYPE DISPLAY PANEL BACKGROUND OF THE INVENTION The invention relates to gaseous display and memory apparatus and more particularly, to apparatus utilizing a pulsing type gaseous discharge chamber.

Prior apparatus using a pulsing-type gaseous discharge cell in which wall charges are manipulated or controlled for storing information and displaying the information is disclosed in an article entitled The Plasma Display PanelA Digitally Addressable Display With Inherent Memory by Bitzer, and Slottow, published in the proceedings of the I966 Fall Joint Computer Conference, Volume 29, pages 54l-547. In this prior apparatus, cells are arranged in a panel-type array containing a single cell or a great number of individual cells, with matrix conductors placed external to the gas cells. This provides isolation between an individual cell and any of the other cells as used in a panel display array. In these prior devices, when X- and Y-axes conductors are energized the gas ionizes at the intersection of the energized wires causing the gas trapped thercbetween to glow and give off a color. No means are provided, however, for multicolor displays.

SUMMARY OF THE INVENTION It is a paramount object of this invention to provide a multicolor display panel utilizing gaseous discharge cells.

It is a further object of this invention to provide electrical control means for controlling the energization of a multicolor gaseous discharge display apparatus.

Briefly, the above objects are accomplished in accordance with the invention by providing two gas chambers, of a single cell or multiple cell type, containing gases which, when ionized, emit different colors. First conductors are provided in an X-axis common to the two gas chambers. Conductors in a first and second Yaxis are provided on opposite sides of each of the gas chambers and orthogonal to the X-axis. All sets of conductors are external to the gas chambers, or within the chambers and electrically insulated from the gas. The first Y- axis conductors are energized by pulses ofa first polarity and phase, and the second Y-axis conductors are energized by pulses of an opposite polarity but the same phase. The gas in one of the chambers is caused to discharge by applying control pulses in phase with the first or second pulses and of an amplitude sufficient to cause the gas at the intersection of the conductors to fire. If the control pulses are of one polarity, the voltage sum across the first chamber is sufficient to cause the gas in the first chamber to ionize. Pulses of the opposite polarity cause the gas in the other chamber to ionize.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded diagram of a display panel constructed in accordance with the invention.

FIG. 2 is a voltage waveform of voltages appearing on the X- and Y-axes control.

FIG. 3 is a cross-sectional view of the display panel shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, an exploded view ofa gaseous display panel is shown. The panel itself is comprised of gas chambers of either a single cell, or a great number of isolated cells, and conductors isolated from the gas chambers by means of insulators. The Yl-axis conductors are comprised of conductive strips placed on insulator 12. A gas chamber 14 is sandwiched between the insulator l2 and another insulator 16 forming the upper and lower walls of the gas chamber, respectively. X-axis conductors 18 are comprised of conductive strips placed on an insulator 20, orthogonal to the Yl-axis, and are sandwiched between the insulator 16 and the insulator 20. A second gas chamber 22 is located between the insulator and another insulator 24 which form the upper and lower walls of the gas chamber 22. Y2-axis conductors 26 are placed on the insulator 24 external to the gas chamber 22 and orthogonal to the X-axis conductors 18.

The gas chamber 14 is filled with a homogeneous gas medium which, when ionized, emits a dominant first color. The gas chamber 22 is filled with a homogeneous gas medium which, when ionized, emits a dominant second color. The gas filling the chambers may be any gas or gas mixture which produces a sufficient discharge such as to cause a rapid flow of charges to the walls of the gas chambers 14 and 22. The conductors l0, l8, and 26 are located on opposite sides of the gas chambers and external to the gas itself so that only the gas at the intersection ofenergized conductors will fire. Discrete wall charges are formed, in accordance with the teachings of the above identified Bitzer et al. publication, on the nonconductive chamber walls adjacent to each of the energized conductors.

The X- and Yl-, Y2-axes conductors are energized in the following manner. Ari oscillator 30 is provided which drives Yl-axis control 32 and X-axis control 34. The output of the oscillator 30 is shifted l by phase shifter 36, the output of which drives YZ-axis control 40. One-half of the voltage required to fire the gas in the chamber 14 is supplied to the Yl-axis conductors 10 by the control 32 in accordance with the waveform A shown in FIG. 2. Identical signals, but of opposite polarity, are applied to the Y2-axis conductors 26 as illustrated in waveform C. The X-axis control 34, in conjunction with switching and selection controls 42, provides for applying voltage pulses to the X-axis conductors 18 in phase with and either of the same polarity or of opposite polarity to the respective pulses constantly supplied to the Yl-axis and the YZ-axis conductors l0 and 26. As shown in waveforms A, B and C, the firing voltage V,-, is reached if the X-axis pulses are of opposite polarity to the Y2-axis pulses, thus forming at the intersection of the selected X- and Y2-axis conductors a voltage of amplitude sufficient to fire the gas of chamber 22 at the intersection and therefore, cause the gas to glow emitting a color of dominant wavelength A 2.

In a similar manner, the gas in chamber 14 is caused to glow, when voltage V, is reached, giving off a color of dominant wavelength A I, by applying pulses to the X-axis which are of opposite polarity to the pulses occurring on the Yl-axis. The voltages applied to the Yl-axis may be greater than, equal to, or less than the voltages on the YZ-axis, depending upon the amplitude of V necessary to fire the gas in chamber 14.

In accordance with the teachings of the above identified Bitzer et al. publication, the amplitude of the output signal at each line 10, 26 is set to one of three levels by switches that are in turn controlled by switching and selection control 42. In a sustaining mode the signals on all lines are at the intermediate voltage level so that the combined signals cross the chambers 14, 22 are all in the sustaining range and the pattern on the display remains unchanged. When the signal on each of two intersecting conductors, for example, the Yl-axis and the X-axis, are raised to the highest level, the combined voltage across the gas chamber 14 at the intersection exceeds the firing voltage V and ionization occurs at the intersection. Similarly, when the signal on these two intersecting lines is reduced to the lowest level, the voltage at the intersection falls to the minimum sustaining voltage and the discharge at the intersection is abnormal. This leaves the cell with such a small wall charge so that even when the signal is increased to the normal sustaining magnitude, the voltage due to the drive signal combined with the voltage due to the wall charges will not reignite the cell.

A cross section of the gas panel of FIG. I is illustrated in FIG. 3. The conductive strips l0, l8 and 26 are 10 mils wide, spaced 40 mils apart center-to-center. The insulating layers 12, 16, 20 and 24 are 3 mils thick, forming gas chambers which are 10 mils thick. These dimensions are given for illustration only, and the invention is not limited thereto. Any suitable dimensions can be used, taking into account the type of gas or gas mixture used, the rate at which the discharge is developed, and the pressure of the gas. The dimensions of the gas chamber should be chosen so that the energization of conductors lit) and 26 will not interact so as to cause an undesired discharge ofthe gases in the chambers M and 22.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in fonn and details may be made therein without departing from the spirit and scope of the invention.

1 claim:

I. A gaseous discharge display panel comprising:

a first gas chamber enclosing an ionizihle gas;

a second gas chamber enclosing an ionizible gas;

a common conductor common to each of said chambers and electrically insulated from the gases therein;

a first conductor at said first chamber, and a second conductor at said second chamber, said first and second conductors orthogonal to said common conductor and electrically insulated from the gases in said chambers;

means for energizing said first conductor with first pulses of a given phase and polarity;

means for energizing said second conductor with second pulses ofa polarity opposite to said given polarity and of the same phase as said given phase; and

means for energizing said common conductor with control pulses in phase with and of the same polarity as said given polarity ofsaid first pulses to thereby cause the gas in said second gas chamber to ionize and with control pulses of opposite polarity to said given polarity and in phase with said first pulses to thereby cause the gas in said first gas chamber to ionize.

2. The combination according to claim ll wherein said first gas chamber is filled with a homogeneous first gas medium which, when ionized, emits a first color, and said second gas chamber is filled with a homogeneous second gas medium which, when ionized, emits a second color.

3. The combination according to claim 1 wherein:

said means for energizing said first conductor includes means for applying to said first conductor first voltage pulses of a fraction of the voltage required to ionize the gas in said first gas chamber;

said means for energizing said second conductor includes means for applying to said second conductor second voltage pulses in phase with and of a polarity opposite to said polarity of said first voltage pulses and of a fraction of the voltage required to ionize the gas in said second chamber; and

said means for energizing said common conductor includes means for applying third voltage pulses to said common conductor in phase with and of a polarity opposite to the polarity of the pulses applied to said first or said second conductors and of sufficient amplitude when added to said first or second voltage pulses to form at the intersection of said conductors a voltage of amplitude sufficient to ionize the gas of said first and second chamber at the intersection of said energized conductors to thereby cause the gas in said first or second chambers to ionize.

4. The combination according to claim 3 including means for varying the amplitude of the voltages applied to said conductors to thereby sustain or not sustain the ionization at the intersection of said conductors.

5. A gaseous discharge display panel comprising:

a first transparent insulating layer;

Yll-axis conductors comprised of conductive strips placed on said first insulating layer;

a second transparent insulating layer;

a first gas chamber sandwiched between said first insulating layer and said second insulating layer, said insulating layers forming the upper and lower walls of said gas chamber, respectively;

a third transparent insulating layer;

X-axis conductors comprised of conductive strips orthogonal to said Yl-mtls conductors and sandwiched between said second and third inmilutlng layers.

a fourth Insulating layer;

a second gas chamber sandwiched between said third and fourth insulating layers forming the upper and lower walls of said second gas chamber, respectively; and

YZ-axis conductors comprised of conductive strips placed 5 on said fourth insulating layer orthogonal to said X-axis conductors.

6. The combination according to claim 5 wherein said first gas chamber is filled with a homogeneous first gas medium which, when ionized, emits a first color, and said second gas chamber is filled with a homogeneous second gas medium which, when ionized, emits a second color.

7. The combination according to claim 95 including:

means for applying to at least one of said Yl-axis conductors first voltage pulses of a fraction of the voltage required to ionize the gas in said first gas chamber;

means for applying second voltage pulses in phase with and of a polarity opposite to the polarity of said first voltage pulses to at least one of said YZ-axis conductors of a fraction of the voltage required to ionize the gas in said second chamber; and

control means for applying third voltage pulses in phase with said first and second voltage pulses to at least one of said X-axis conductors of opposite polarity to the polarity of either the pulses applied to said Yllor said YZ-axes conductors and of sufficient amplitude when added to said first or second voltage pulses to form at the intersection of said X- and Ylor YZ-axes conductors a voltage of amplitude sufficient to ionize the gas of said first or second chambers at the intersection of said energized conductors to thereby cause the gas in said chamber to ionize.

b. The combination according to claim 7 including means for varying the amplitude of the voltages applied to said Y1- and YZ-axes conductors to thereby sustain or not sustain the ionization at the intersection of said conductors.

9. A gaseous discharge display panel comprising:

a first gas chamber enclosing a gas which, when ionized,

emits a color of dominant wavelength A l;

a second gas chamber enclosing a gas which, when ionized,

emits a color of dominant wavelength A 2;

a first conductor common to each of said chambers and electrically insulated from the gases therein forming part of an array of conductors in a first axis;

a second conductor at said first gas chamber, and a third conductor at said second gas chamber, said second and third conductors orthogonal to said first axis and electrically insulated from the gases in said chambers;

means for energizing said second conductor with first pulses ofa given polarity;

means for energizing said third conductor with second pulses in phase with said first pulses and of a polarity opposite to said given polarity; and

means for energizing said first conductor with control pulses of opposite polarity to the polarity of in phase with and said first pulses to thereby cause said second gas to ionize and emit a color of wavelength A 2, and with control pulses of opposite polarity to the polarity of said second pulses to thereby cause said first gas to ionize and emit a color of wavelength A 1.

R0. The combination according to claim 9 including:

means for applying to said second conductor first voltage pulses of a fraction of the voltage required to ionize the gas in said first gas chamber;

means for applying second voltage pulses in phase with and of a polarity opposite to the polarity of said first voltage pulses to said third conductor of a fraction of the voltage required to ionize the gas in said second chamber; and

control means for applying third voltage pulses to said first common conductor of opposite polarity to the polarity of, in phase with and the pulses applied to said second or said third conductor and of sufi'icient amplitude when added to said first or second voltage pulses to form at the intersection of said first and second or third conductors a voltage of amplitude sufficient to ionize the gas of said first or second chamber at the intersection of said energized conductors to thereby cause the gas in said chamber to ionize.

,1,, UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 31588 1 Dat d August 12 197].

Inventor(s) Donald D. Tech It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

5- Column 4, line 55 after the word "pulses" insert -in phase with and-. Column 4, line 56 after the word "of" second occurrence delete "in phase with and". Column 4, line 71, after the word "conductor" insert --in phase with and--.

Column 4, line 72, before the word "the" delete "in phase with and".

Signed and sealed this 25th day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR.

ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

